1. Field of the Invention
This invention relates to a magnetic coupling device for charging an electric car.
2. Description of the Related Art
A conventional charging connector, which has been put into practical use for charging an electric car, includes a car-side connector, which is mounted on the electric car, and is connected to a car battery, and a power supply connector connected to a charging power source provided outside the car. Therefore, when the car-side connector and the power supply connector are fitted together, electric power is supplied from the charging power source to the car battery, thereby charging the car battery. Terminals of the car-side connector and the power supply connector are fittingly connected together by a male-female fitting construction to form electric paths. However, this structure creates a problem that a large resistance to the fitting operation is involved.
Therefore, a method has been proposed of effecting the charging operation without directly fitting the two connectors together, in which each of the car-side connector and the power supply connector includes a core and a coil, and electric power is supplied from the power supply side to the car side by electromagnetic induction current between the coils.
In this case, however, the cores and coils for the magnetic circuit need to be provided, and the size and weight of the connectors is increased.
Also, the car-side connector of this proposed method is always mounted on the electric car. Therefore if the size of the car-side connector is increased, a large mounting space must be provided in a car body, and also the design of the car body is limited greatly. Further, if the weight of the car-side connector is increased, the running performance is lowered.
On the other hand, in some cases, it is expected that the power supply connector be handy and portable. In such a case, the power supply connector is required to have a lightweight design.